Grant Morrison: Superman. The only writer who I trusts with anything in comics but he REALLY gets superman. From JLA, All Star Superman to Action Comics he revitalized superman as a paragon of strength, morality and leadership when the modern writers tried too hard to humanize him and often got what makes superman a hero wrong.
Peter David: Hulk. God I love his hulk. The quintessential hulk writer.
John Ostrander: Martian Manhunter and Spectre.
Mike Carey: Lucifer
Alan Moore: Too many stories to name.